OldIHC

I'm replacing my head gasket and getting some repairs done to the head on my 51 international L110 and was wondering if I should clean the in take manifold and what's the best way to get it cleaned. Any help would be greatly appreciated

Why do you think the manifold needs cleaning? Do you see lumps and other debris inside? Sandblasting or wire brushing the outside to make it look better can't hurt. If you decide to use sand blast, be sure to get all of the sand out before putting it back in service.
It is very important to tighten all the manifold bolts together in stages. It is possible to break the manifold if the bolts are tightened fully starting from one end.

Was just wondering after removing the manifold from the head I noticed that the ports are black and thought the cleaner the better for the air and gas. I'm new to this and haven't seen what they should look like.

If there is no obstruction, forget about it.

Thanks for the info